A switched inductance ac-dc circuit and its inductance adaptive control method

Abstract

The invention discloses a switched inductance AC-DC circuit and its inductance self-adaptive control method, comprising: a filter circuit, a rectifier circuit, a first-stage interleaved circuit and a second-stage interleaved circuit; filtering; the rectification circuit is used to rectify the filtered AC voltage; the first stage interleaved circuit is used to perform the first step-up and the first power factor correction on the DC voltage; the second stage interleaved circuit is used to perform the first step on the DC voltage Second step-up and second power factor correction; the switching period of the second-level interleaving circuit lags behind the switching period of the first-level interleaving circuit. The method includes: determining parameters; detecting real-time voltage deviation; calculating the maximum duty ratio of the power switch according to the DCM mode principle; calculating the corresponding duty ratio of the power switch; calculating the duty ratio and phase shift of the corresponding power switch; controlling the corresponding power switch on and off. Through the present invention, the voltage impact caused by the sudden change of current can be avoided, and the load capacity can be improved.

Description

technical field [0001] The invention relates to the technical field of power electronic conversion, in particular to a switched inductance AC-DC circuit and an inductance self-adaptive control method thereof. Background technique [0002] In the Proceedings of the 13th IEEE Conference on Industrial Electronics and Applications (ICIEA2018) in 2018, Wang Faqiang and others proposed a switched-inductor (Switched-inductor) power factor correction circuit (PFC), that is, a single-phase AC-DC circuit, including Two energy storage branches and one freewheeling branch have the characteristics of fewer components, no step-up transformer, high voltage gain and unit power factor of the grid side. [0003] In one switching cycle, the working process of the entire AC-DC circuit is divided into three stages: (1) The two power switches of the two energy storage branches are turned on at the same time, the two inductors are charged independently, the current rises and the energy is stored; ...

AI Technical Summary

Problems solved by technology

Only when discontinuous current mode (DCM) is used, when the inductance value is different, there is a control algorithm that may enable the AC-DC circuit to work, but certain conditions must also be met to prevent the circuit from entering CCM

That is, when the inductance values ​​are different, it must be ensured that the two inductors are discharged at the same time and the discharge instantaneous current is equal, and a margin is reserved to accommodate heavy loads, high switching frequency, network voltage RMS drop and inductance value increase. Potential CCM, which is The only solution, but this information is not disclosed in the existing literature

[0007] In addition, the switched-inductor power factor correction circuit (PFC) proposed by Wang Faqiang et al. has a low load capacity and does not provide a grid-side filter circuit. Due to the use of DCM, the design of the network current filter is more difficult. Therefore, It is necessary to design an interleaved structure in order to solve the difficulty of carrying capacity and grid-side filter circuit design

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